Fan



Mar. 6, 1923'.

w. A. JONES 'FAN Filed Apr. 5, 1919 3 sheets-sheet l INVENTOR.

W. A. JONES FAN 5 sheets-sheet 2 Filed Apr.

INVENTOR.

WITNESSES Mar. 6, 1923.,

1,447,554 W. A. JONES FAN Filed Apr. 5, 1 1

3 sheets-sheeo 5 Patented Mar. 6, 1923.

warren stares WILLIAM ANTHONY'JON'E S, OF WEST NEW BRIGHTON, NEW YORK?FAN.

Application filed April 3, 1919. Serial No. 287,273.

To all whom it mar/y concern Be it known that I, l/VILLIAM ANTHONYJoNEs, a citizen of the United States, and resident of West NewBrighton, county of Richmond, and State of New York, haveinvented-certain new and useful Improvements in Fans, of which thefollowing is a which results from a chimney in order to cause gases toflow through passages provided forthcm and through various heatabsorbing apparatus.

It frequently happens that the products of combustion are charged with aquantity of fine dust which it is desired to separate from the gases.

In the case of cement kilns the dust which is carried away by the wastegases is very valuable.

In the case of burning finesizes of hard coal the dust which is carriedout of the stack is objectionable in the neighborhood.

Ordinary centrifugal fans receive gas at the center, parallel to theaxis, and discharge it radially, which necessitates a right-angle changeof direction of the gases and makes it difficult to obtain a gradualdecrease and increase of gas passage cross-sectional area with acorresponding gradual increase and decrease of gas velocity whichconduces to efliciency. I

Ordinary disc fans operate on gas at widely different distances'from thecenter, and it is impossible to have equally good efficiency at allpoints. Ordinary disc fans act on the gas without imparting anyconsiderable rotary motion to the gas and the axial motion which theyimpart to the gas is accompanied by a heavy axial thrust on-the fan.

In the accompanying drawings, Figure 1 is a longitudinal section throughthe fan and easing. Figure 2 is an end View, partly in section on theline AA'of Figure l, of the discharge end of the casing. Figure 3 showsa part view of the fan wheel. Figure 4 is a development of a cylindricalsurface concentrio with the axis and shows the intersection of thissurface with the blades of the fan and with the stationary guide vanesat each side of the fan. Fig. 5, is a plan view of my fan connected to asettling chamber. Fig. 6, is a vertical view, partly in section, of thestructure shown in Fig. 5. Fig. 7 is a part section through the fancasing and bearings and shows pipes for conveying a cooling medium forthe bearings. Fig. 8 is a development of a cylindrical surfaceconcentric with the axis and shows the intersection of this surface withthe blades of the fan and with stationary guide vanes at each side ofthe fan, Fig. 8 is like Fig. 4 except that an arrow, 88, is shown torepresent the path of a particle of dust, and arrows, NP, are shown torepresent pressures normal to the guide vanes and normal to the bladesof the fan. Fig. 9 is a part section on the line, GG, through theoutlet, Q, for dust and-shows a View in plan of the arrow, 88.

Similar parts are referred to by similar letters throughout the severalviews.

Referring to the drawings: a fan wheel a, provided with blades 1), ismounted on a shaft 0. A gear d is fastened to the fan wheel and isdriven by pinion wheel 6 mounted on shaft f which extends outside of thefan casing.

The fan casing is represented as made of an inletpart g and an outletpart it. A conical shield 2', concentric with the inlet part g of thefan casing, shields the central part of the fan wheel a. A similarconical shield j shields the central part of the fan wheel at the otherside in the outlet' part it.

The space k, between the conical shield Wand the inlet part g of thecasing, forms a passage of gradually decreasing cross-sectional area forgas as it approaches the fan wheel blades 7). Stationary guide vanes lin the space 71;, between the conical shield i and the casing g,determine the direction, of flow of gas to the wheel. Similar stationaryguide vanes m, in the space 4 between theconical shield j and the casingh, determine the direction of flow of the gas as it leaves the blades ofthe wheel. Inclination of the stationary guide vanes l and m, withrespect to the axis, causes an axial thrust of the gases without acoresponding axial thrust on the fan wheel.

In additiog to the outlet passage a, a

second outlet passage 0, at a greater disoi the blades is also showngreater at the outlet side of the tan wheel for the same reason. I

The passage 0 for dust leads toorifice Q. from which dust may beconducted to a settling chamber. ln the settling chamber the velocity ofthe gas from the orifice Q may be reduced so that dust will bedeposited. and this relatively small volume of gas may then be led tothe inlet end of the fan again.

Figs. 5 and 6 show a settling chamber, cc, ol circulanform which isrepresentative of one form of such a settling chamber. In thisrepresentation. dust laden gas enters the settling chamber tangentially.from the outlet. 0". maintaining a rotary motion of the gases within thechamber. Gases pass below the lower edge of a circular internal bailleand then flow upward to the top of the chamber from which they may beconducted by ,the pipe. w. to the inlet side of the fan. The slowvelocity of the gases in the large chamber and the change in thedil'iection of their flow causes the dust, with which the gases areladen, to be deposited in the dust settling chamber. The conical bottomof the chamber facilitates the dust being drawn oil through the valvedopening, cw.

In its passage through the fan, the pressure ol the gas will be least atthe fan wheel where the velocity of the gas will be greatest. that is tosay. the pressure at r. between the blades of the fan wheel. will beless than the pressure. at a. at the inlet, or atf". at the outlet.

Ordinarily. therefore. it will be possible to cool the bearings 71/ or-the fan shaft c and pinion shatt f by allowing airto flow to thesehearings through pipes from the atmosphere external to the casing, andsuch air may be discharged into the space within the conical shields'1'" and j from which it will flow through space r to mingle with thegases being acted upon by the fan.

()r. bearings may be cooled by water or by oil conducted to and from thebearings by suitable pipes pp and go, one arrangement of which is shownin Fig. 7.

A shield w, attached to the fan Wheel and projecting within a flange mof the conical shield i, is represented for retaining the oil used forlubricating gears d and e.

The blades 1) of the fan wheel a are represented in planes passingthrough the axis. This results in no end thrust on the fan wheel and ina relatively slow speed of fan wheel for a given velocity of gas.

By making the planes of the blades oblique to the axis with a retreatingangle 3 with reference to the planes of the blades shown. the speed ofthe fan wheel may be increased with the same velocity of gas. lVhenoblique blades are used, there is an axial thrust on the tan. less thanthat of an ordinary disc fan, but the higher speed permits a high speedmotor to be direct-connected to the fan without the necessity ofreduction gears, even for low velocities of gas.

The action of the fan in causing gas to flow from a lower pressure to ahigher pressure is as follows. Rotation of the fan wheel draws gas awayfrom the spaces between the stationary vanes at the inlet side of thefan wheel and reduces the pressure at that point and this in turn causesgases to flow between the stationary vanes. at the inlet side. to thetan wheel. The gradual decrease in cross section of gas passage area atthe inlet side permits the gases to acquire a relatively high velocityas they reach the wheel without the formation of eddies. In this respectthe action of the gas passage of gradually decreasing cross section islike the action of a Venturi tube, the wheel of the fan being at thethroat.

The efficiency of my invention is high because. like a Venturi tube. itis adapted to convert pressure into velocity, at the inlet side, andvelocity into pressure. at the outlet side, and also be arise in passingthrough the apparatus gas has a very short path and for only a smallpart of that short path is it at high velocity. The first of thesefeatures reduces loss from eddies to a minimum and the second reducesloss from skin friction to a minimum.

The gradual increase in cross sectional area of the gas passages fromthe outlet side of the wheel is also like a Venturitube and.

effectively converts velocity into pressure.

The absence of axial thrust on the moving wheel also reduces loss andwear. The apparatus is particularly adapted for use as a vacuum cleaner.The thrust bearings of other vacuum cleaner tans wear out in a shorttime and the dust bags of such vacuum cleaners require frequent cleaningand offer resistance'to the passage of air.

The cross sectional area for gas flow at the wheel is even less than itappears at first glance being the difference in area of the circle ofthe body of the wheel and the area of the circle of the inside of thecasing, multiplied by the sine of the angle of inclination of thestationary vanes. This disregards the thickness of the blades of thewheel.

As shown on the drawings the area of gas flow at the wheel,corresponding to the throat of a- Venturi tube, is abou'tone sixth ofthe area of gas flow at the inlet and at the outlet. If it is desired tohandle gas against about seven inches of water pressure, correspondingto a velocity head of 475 feet for air at normal temperature, then theyas velooity at the wheel would be about 1 5 feet per second and thevelocity ofthe blades of the Wheel would be about 125 feet per second.Of course the proportions are varied to suit conditions.

In the conditions assumed above the velocity at the inlet would be aboutonesixth the velocity at the wheel, or about 29,feet per second, 1750feet per minute.

The fact that, disregarding friction, the sum ofthe dynamic head and thepressure head is a constant in a Venturi tube is the basis of theVenturi' meter, where the decrease in pressure head at the throat, Wherethe velocity is highest, is used to calculate the velocity of flow.

In the ordinary Venturi tube the final pressure is slightly less thanthe initial-pressure due to friction.

In my. invention the blades of the {an wheel add to the velocity at thethroatso that the final pressure is greater than the initial pressure.

The fact that the energy of motion is as the square of the velocity,makes it necessary to add only a small amount to the relatively highvelocity, which the gas has when it reaches the wheel, in order to addsuflicient kinetic energy to the gas to enable it to enter the higherpressure at the outlet of the fan. This relatively small increase invelocity is evidently accompanied with much less disturbance and loss ineddies and impact than when the blades of a fan wheel bite intostationary gas or gas flowing slowly in passage ways of relatively largecross sectional area, so that adjacent parts of the gas are suddenlytornaway at high velocity.

With the proportions shown on the drawings and described above, in myinvention,

the blades of the fan wheel practically exert is moving tangentially tothe conical shield and also in the direction of the stationary guidevane which is next to this particle of dust. By reason of its inertia,the particle of dust will tend to move forward in this direction in astraight line and in a given interval of time its distance from the axisof the fan will increase from R to R During this interval of time itstransverse motion will be equal to the length of the line, L, and itslongitudinal motion will be equal to the length of the line, L Evidentlywith the relative proportions shown, the direction of motion of thisparticle of dust will carry it into the outlet for dust, 0.

Evidently if the angle of the cone were less without increasing thewidth of the wheel or the Wheel were made narrower without increasingthe angle of the cone, then the direction of motion of this particle ofdust, which is tangent to the cone,

ing, '0, for dust. Again thisobject would not be attained if thediameter of the base of the cone were made smaller without makingcorresponding changes in the other dimensions of the fan.

The above shows that, with the proportions shown, the particle of dustnext to the conical shield at the inlet side of the fan will be carriedto the outlet for dust, 0. Evidently all other particlesof dust whichare would not carry the particle into the openinitially at a greaterdistance from the axis of the fan, will have a less radial distance togo and will also be carried to the outlet for dust, o.

The particular arrangement shown may be altered without departing fromprinciple of the invention.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. In apparatus for causing gas to flow from a lower pressure to ahigher pressure, the combination of a shaft with bearings, a fan wheelwith blades, a casing having a concentric conical shield at the inletside of the fan wheel, and a second concentric conical shield at theoutlet side of the fan wheel, stationary vanes, oblique to the axis,between the conical shields and the shell of the casing, an inlet for.gas at one side of the fan wheel, an outlet for gas at the other side ofthe fan wheel, a second outlet for dust at a greater distance from thecenter than the first outlet, stationary vanes for determiningthed'irection of flow of dust from the fan wheel blades to the secondoutlet, passages for conducting a cooling medium to the bearings.

v 2. In apparatus for causing gas to flow from a lower pressure to ahigher pressure, the combination of a shaft with bearings, a fan wheelwith blades, a casing having a concentric conical shield at the inletsideof the fan wheel, and a second concentric conical shield at theoutlet side of the fan wheel, stationary vanes, oblique to the axis,between the conical shields and the shell of the easing, an inlet forgas at one side of the fan wheel, an outlet for gas at the other side ofthe fan wheel, a second outlet for dust at a greater distance from thecenter than the first outlet, stationary vanes for determining thedirection of flow of dust from the fan wheel blades to the secondoutlet.

3. In apparatus for causing gas to flow from a lower pressure to ahigher pressure, the combination ofa" shaft with bearings, a fan wheelwith blades, a casing having a concentric conical shield at the inletside of the fan wheel, and a second concentric conical shield at theoutlet side of the fan wheel, stationary vanes, oblique to the axis,between the conical shields and the shell of the easing, an inlet forgas at one side of the fanwheel, an outlet for gas at the other. side ofthe fan wheel, a second outlet for dust at a greater distance from thecenter than the first outlet.

4:. In apparatus for causing gas to flow from a lower pressure to ahigher pressure, the combination of a fan wheel with blades, a casinghaving a conical shield at the inlet side of the fan wheel, a secondconical shield at the outlet sideof the fan wheel, stationary vanesbetween the conical shields and the shell of the casing, the crosssectional area for flow of gas being least at the fan wheel andgradually increasing at each side of the fan wheel, substantially asdescribed.

5. In apparatus for causing gas to flow from a lower pressure to ahigher pressure, the combination of a fan wheel with blades, a casinghaving a conical shield at the inlet side of the fan wheel, a secondconical shield at the outlet side of the wheel, stationary vanes betweenthe conical shields and the casing, with the vanes curved so that theyare oblique to the axis near the fan wheel and are parallel to the axisat the point farthest from the fan wheel. the cross sectional area forflow of gas being least at the fan wheel and gradually increasing ateach side.

6. In apparatus for causing gas to flow from a lower pressure to ahigher pressure,

- the combination of a shaft with bearings, a

. cal shield at the outlet side of the fan wheel,

outlet side of the fan wheel, stationary vanes, oblique to the axis,between thr coni cal shields and the casing, all so that rotation of thefan wheel causes rotation of the gas at the fan wheel and the obliquestationary vanes cause an axial thrust on the gas, the cross sectionalarea. for flow of gas being least at the fan wheel where the velocity ofgas is greatest, substantially as described.

-8. In apparatus for causing gas to flow from a lower pressure to ahigher pressure, the combination of a fan wheel with blades whosesurfaces are formed of lines which are parallel to the axis of the fanwheel so that a pressure normal to the surfaces will not cause an axialthrust on the fan wheel, a casing, a conical shield at the inlet side ofthe fan wheel, a second conical shield at the outlet side of the tanwheel, stationary vanes, oblique to the axis, between the conicalshields and the casing, all so that rotation of the fan wheel causesrotation of the gas at the fan wheel and the oblique stationary vanescause an axial thrust on the gas, the cross sectional area for flow ofgas being least at the fan wheel where the velocity of the gas isgreatest, substantially as described. 9. In apparatus for causing gas toflow from a lower pressure to a higher pressure, the combination of ashaft with bearings, a fan wheel with blades, a casing havingaconcentric conical shield at the inlet side of the fan wheel, and asecond concentric conical shield at the outlet side of the fan wheel,stationary vanes. oblique to the axis, between the conical shields andthe shell of the easing, an inlet for gas at one side of the fan wheel,an outlet for gas at the other side of the fan wheel, a second outletfor dust at a greater distance from the center than the first outlet, achamber for settling dust, a

connection from the outlet for dust to the chamber for settling dust.

WILLIAM ANTHONY JONES.

Witnesses: I

BENJ. B. WHITTAM, I HEBER C. Insnnn.

